To study the mechanisms which produce lesions in the arterial intima of the experimental animal and to compare the lesions produced and mechanisms involved with those in human arteries. In particular, to study the effect of hypertension on the development of arterial lesions both thrombotic and those produced by hyperlipemia and passage of lipids, cells and other materials across the arterial endothelium with and without the presence of raised arterial pressures. BIBLIOGRAPHIC REFERENCE: "The effect of Triton on the arterial endothelium: A scanning and transmission electron microscopic study." W. J. S. Still. Arterial Wall 11:87-103, 1975.